Zhao Xueqing, Liao Zitong, Liu Tongtong, Cheng Wei, Gao Ge, Yang Mingbo, Ma Ting, Li Guoqiang
Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China.
Tianjin Engineering Technology Center of Green Manufacturing Biobased Materials,College of Life Sciences, Nankai University, Tianjin 300071, China.
J Appl Microbiol. 2023 Dec 1;134(12). doi: 10.1093/jambio/lxad281.
Microbial enhanced oil recovery (MEOR) is dedicated to enhancing oil recovery by harnessing microbial metabolic activities and their byproducts within reservoir rocks and fluids. Therefore, the investigation of microbial mobility and their extensive distribution within crude oil is of paramount importance in MEOR. While microscale models have been valuable for studying bacterial strain behavior in reservoirs, they are typically limited to 2D representations of porous media, making them inadequate for simulating actual reservoir conditions. Consequently, there is a critical need for 3D models and dependable visualization methods to observe bacterial transport and metabolism within these complex reservoir environments.
Bacterial cellulose (bc) is a water-insoluble polysaccharide produced by bacteria that exhibits biocompatibility and biodegradability. It holds significant potential for applications in the field of MEOR as an effective means for selective plugging and spill prevention during oil displacement processes. Conditionally cellulose-producing strain, FY-07-G, with green fluorescent labeling, was engineered for enhanced oil recovery. 3D micro-visualization model was constructed to directly observe the metabolic activities of the target bacterial strain within porous media and to assess the plugging interactions between cellulose and the medium. Additionally, X-ray computed tomography (X-CT) technology was employed for a comprehensive analysis of the transport patterns of the target strain in oil reservoirs with varying permeabilities. The results indicated that FY-07-G, as a microorganism employing biopolymer-based plugging principles to enhance oil recovery, selectively targets and seals regions characterized by lower permeability and smaller pore spaces.
This work provided valuable insights into the transport and metabolic behavior of MEOR strains and tackled the limitation of 2D models in faithfully replicating oil reservoir conditions, offering essential theoretical guidance and insights for the further application of oil-displacing bacterial strains in MEOR processes.
微生物强化采油（MEOR）致力于通过利用储层岩石和流体中的微生物代谢活动及其副产物来提高采收率。因此，研究微生物在原油中的迁移性及其在原油中的广泛分布在微生物强化采油中至关重要。虽然微观模型对于研究储层中细菌菌株的行为很有价值，但它们通常仅限于多孔介质的二维表示，不足以模拟实际储层条件。因此，迫切需要三维模型和可靠的可视化方法来观察这些复杂储层环境中的细菌运输和代谢。
细菌纤维素（bc）是细菌产生的一种水不溶性多糖，具有生物相容性和生物降解性。作为驱油过程中选择性封堵和防泄漏的有效手段，它在微生物强化采油领域具有巨大的应用潜力。对具有绿色荧光标记的条件性纤维素生产菌株FY-07-G进行工程改造，以提高采收率。构建了三维微观可视化模型，直接观察目标细菌菌株在多孔介质中的代谢活动，并评估纤维素与介质之间的封堵相互作用。此外，采用X射线计算机断层扫描（X-CT）技术对目标菌株在不同渗透率油藏中的运移模式进行了综合分析。结果表明，FY-07-G作为一种利用生物聚合物基封堵原理提高采收率的微生物，选择性地靶向并密封渗透率较低和孔隙空间较小的区域。
这项工作为微生物强化采油菌株的运输和代谢行为提供了有价值的见解，解决了二维模型在忠实复制油藏条件方面的局限性，为驱油细菌菌株在微生物强化采油过程中的进一步应用提供了重要的理论指导和见解。
